Modern commercial vehicles with a pneumatic brake installation have an electronic brake system that actuates an electropneumatic control unit (modulator), which shortens the reaction time for braking and furthermore provides further functions, such as antilock control, antiskid control, etc. The electronic brake system typically also includes a brake controller that controls the operation of the modulator. The modulator and the brake controller are typically combined in one unit.
Trailers with a pneumatic brake installation likewise have an electronic brake system with a brake controller and a trailer modulator. Towing vehicles and trailers can be connected to one another via two pneumatic lines (supply pressure and brake pressure) and an electrical line.
In Europe, the electrical line contains a standardized data connection between the brake controller of the towing vehicle and the brake controller of the trailer. The data connection is used to transmit brake signals from the towing vehicle to the electronic brake system of the trailer without delay.
In North America, trailers obtain brake signals only via the pneumatic line carrying the control pressure. As a result, the time before the brakes in the trailer respond is much longer than in trailers in Europe. A wireless connection of towing vehicle and trailer is disclosed in EP 1 186 510 A1.
However, a wireless connection to the electronic brake system of the trailer carries significant risks.